Systems and methods for cancellation of cross-coupled noise

ABSTRACT

Systems and methods for canceling cross-coupled satellite signals in a LNB IC include receiving a first satellite signal at a first pin of the LNB IC and adjusting the first satellite signal by applying a first adaptive filter to the first satellite signal signal, the first adaptive filter having first filter coefficients; combining the adjusted first satellite signal with a second satellite signal received at a second pin of the LNB IC to generate a first combined satellite signal; measuring the total output power of the combined satellite signal; changing the filter coefficients of the first adaptive filter; remeasuring the total output power of the first combined satellite signal after the changing of the first filter coefficients to determine whether the total power of the first combined satellite signal has decreased.

TECHNICAL FIELD

The disclosed technology relates generally to satellite communications,and more particularly, some embodiments relate to improved signalprocessing techniques for satellite signals.

DESCRIPTION OF THE RELATED ART

Satellite television and other satellite communications have becomemainstream in today's society. For example, satellite dishes and outdoorreceiver units are common sights in commercial and residential areas.FIG. 1 is a diagram illustrating a typically outdoor unit. Referring toFIG. 1, a satellite receiver outdoor unit (ODU) 110 typically comprisesa dish antenna 150, one or more antenna feed horns 130, one or more lownoise amplifier and block down converters (LNB) 140, and an optionalmultiport cross point switch 160. Dish 150 collects and focuses receivedsignal power onto antenna feed horns 130 which couples the signal toLNBs 140. A single dish 150 may have multiple feed horns 130 whereineach feed receives a signal from a different satellite in orbit. Aninstallation may have more than one dish, feed, and LNB assemblies. Thecross point switch 160 allows connection of the outdoor unit 110 to morethan one integrated receiver decoder (IRD) 180 located inside thebuilding. IRDs are commonly called set top boxes (STBs) arising fromtheir typical installed location on top of TV sets. The LNB 140 convertsthe signal transmitted by a satellite in Earth orbit, for example Cband, Ku band, or another frequency band, to a lower intermediatefrequency (IF) suitable for transmission through coax inside a building.For example, L band IF (950 to 1450 MHZ) with RG-6 or RG-11 coax cableis commonly used. The IRD 180 tunes one transponder channel, demodulatesthe IF signal from the LNB down to base band, provides channelselection, conditional access, decodes the digital data to produce avideo signal, and generates an RF output to drive a television.

A satellite outdoor unit may have as many as three or more LNBs eachwith two receiving polarizations. The received polarization is selectedby sending a voltage or other control signal to the LNB. In thisconfiguration, six possible 500 MHz signals may be selected by themultiport cross point switch to be routed to each IRD. The 500 MHzsignal is typically comprised of 16 transponder signals of 24 MHzbandwidth each with a guard band in between each transponder signal.Other transponder bandwidths may be used, such as 36 MHz or 54 MHz(either a single channel or shared by two TV signals) and 43 MHz.

FIG. 2 is a diagram illustrating an example implementation of a lownoise block 140. In this example, the low noise block LNB receiveshorizontally and vertically polarized signals from the satellite. Foreach polarization, low noise block includes one or more low noiseamplifiers (LNA) 141 to amplify the received signal to an acceptablelevel for processing. Preferably, the amplification may be done as closeto the signal source (e.g., the antenna) as possible to avoid amplifyingadditionally introduce noise. The amplified received signal can bepassed through a bandpass filter 142 to filter out unwanted noise fromthe signal. A down converter 143 can be used to downconvert the receivedsignal to an intermediate frequency or directly to a desired frequencyfor distribution. In this example, the down converter includes a mixerand a local oscillator at the desired frequency (e.g., 9.75 GHz or 10.6GHz). The downconverted signal can be further filtered and amplifiedprior to distribution. This is illustrated by low pass filter (LPF) 144and amplifier (AMP) 146. Switches 147 can be provided to allow selectionand placement of the desired signal onto a selected output. Additionalamplifiers 148 can also be provided for distribution of the signals suchas, for example, along the cable drop. A switch control module 149 canalso be provided to control selection of the matrix which is 147. Switchcontrol, for example, can respond to commands from the set top boxes toensure delivery of desired program content accordingly.

FIG. 3 is a diagram illustrating another example of a low noise block(LNB) 140. The example illustrated in FIG. 3 in particular is an exampleof a wideband LNB. Similar to the example illustrated in FIG. 2, thisLNB 140 includes low noise amplifiers 141, and pass filters 142,downconverters 143, and low pass filters 144. However, because theexample of FIG. 3 is a wideband system, the output for each polarization(horizontal and vertical) or on a single output, which in this instancecovers 290-2340 MHz, or approximately 2 GHz in bandwidth.

BRIEF SUMMARY OF EMBODIMENTS

According to various embodiments of the disclosed technology, a methodfor canceling cross-coupled satellite signals in a LNB IC, may include:receiving a first satellite signal at a first pin of the LNB IC andadjusting the first satellite signal by applying a first adaptive filterto the first satellite signal, the first adaptive filter having firstfilter coefficients; combining the adjusted first satellite signal witha second satellite signal received at a second pin of the LNB IC togenerate a first combined satellite signal; measuring the total outputpower of the combined satellite signal; changing the filter coefficientsof the first adaptive filter; and remeasuring the total output power ofthe first combined satellite signal after the changing of the firstfilter coefficients to determine whether the total power of the firstcombined satellite signal has decreased.

In various embodiments, the cross-coupling cancellation may also includedelaying the second received satellite signal prior to combining it withthe adjusted first satellite signal. In further embodiments, thecross-coupling cancellation may also include repeating the operations ofchanging the filter coefficients and remeasuring the total output powerof the first combined satellite signal after the change until themeasured total output power reaches a minimum value.

The cross-coupling cancellation may also include repeating theoperations of changing the first filter coefficients and remeasuring thetotal output power of the first combined satellite signal after thechange. It may further include minimizing the total output power of thefirst combined satellite signal by repeating the operations of changingthe first filter coefficients and remeasuring the total output power ofthe first combined satellite signal until a minimum power level isreached. The operation can, in some embodiments, include repeating theoperation for additional pairs satellite signals.

In various embodiments, the first adaptive filter applied may include aleast mean square filter.

Embodiments may be implemented in which the cross-coupling cancellationalso includes repeating the operation for a remaining number of p pairsof satellite signals, where p comprises a number of possible pairings ofsatellite signals in the LNB. Other embodiments may be implemented inwhich the cross-coupling cancellation also include repeating theoperation for a remaining number of pairs of p pairs of satellitesignals, where p is given by n!/2(n−2), where n is the number ofsatellite signals under consideration.

In some embodiments, the operation further includes adjusting the secondsatellite signal by applying a second adaptive filter to the secondsatellite signal, the second adaptive filter having second filtercoefficients; combining the adjusted second satellite signal with thefirst satellite signal received at the first pin of the LNB IC to form asecond combined signal; measuring the total output power of the secondcombined satellite signal; changing the filter coefficients of thesecond adaptive filter; and remeasuring the total output power of thesecond combined satellite signal after the changing of the second filtercoefficients to determine whether the total power the second combinedsatellite signal has decreased.

Systems and methods can be implemented in which a low noise block ICincludes: a plurality of input pins each configured to receive asatellite signal; a plurality of delay modules, each delay module havingan input coupled to a corresponding input pin and an output to output adelayed satellite signal; a plurality of adaptive filter modules, eachadaptive filter module having an input coupled to a corresponding inputpin; a plurality of signal combiners, each signal combiner having inputscoupled to an output of a corresponding delay module and an output of acorresponding adaptive filter module, and each signal combinerconfigured to output a combined satellite signal.

The LNB IC may further include a filter coefficient computation module,comprising computer executable program code embodied on a non-transitorymedium and configured to cause the filter coefficient computation moduleto perform the operations of: measuring the total output power of thecombined satellite signal from a first one of the plurality of signalcombiners; changing the filter coefficients of the adaptive filtercorresponding to the first one of the plurality of signal combiners;remeasuring the total output power of the combined satellite signal fromthe first one of the plurality of signal combiners after the operationof changing the filter coefficients to determine whether the total powerof the combined satellite signal from the first one of the p signalcombiners has decreased.

In various embodiments, the computer executable program code is furtherconfigured to cause the filter coefficient computation module to repeatthe operations of changing the filter coefficients and remeasuring thetotal output power of the first combined satellite signal after thechange until the measured total output power reaches a minimum value.

In other embodiments, the computer executable program code is furtherconfigured to cause the filter coefficient computation module to repeatthe operations of changing the first filter coefficients and remeasuringthe total output power of the first combined satellite signal after thechange.

In still further embodiments, the computer executable program code isfurther configured to cause the filter coefficient computation module toperform the operations of minimizing the total output power of the firstcombined satellite signal by repeating the operations of changing thefirst filter coefficients and remeasuring the total output power of thefirst combined satellite signal until a minimum power level is reached.

In another embodiment, the computer executable program code is furtherconfigured to cause the filter coefficient computation module to repeatthe operations for additional pairs satellite signals.

In yet another embodiment, the computer executable program code isfurther configured to cause the filter coefficient computation module torepeat the operations for a remaining number of p pairs of satellitesignals, where p comprises a number of possible pairings of satellitesignals in the LNB.

In still further embodiments, the computer executable program code isfurther configured to cause the filter coefficient computation module torepeat the operations for a remaining number of pairs of p pairs ofsatellite signals, where p is given by n!/2(n−2), where n is the numberof satellite signals under consideration.

Other features and aspects of the disclosed technology will becomeapparent from the following detailed description, taken in conjunctionwith the accompanying drawings, which illustrate, by way of example, thefeatures in accordance with embodiments of the disclosed technology. Thesummary is not intended to limit the scope of any inventions describedherein, which are defined solely by the claims attached hereto.

BRIEF DESCRIPTION OF THE DRAWINGS

The technology disclosed herein, in accordance with one or more variousembodiments, is described in detail with reference to the followingfigures. The drawings are provided for purposes of illustration only andmerely depict typical or example embodiments of the disclosedtechnology. These drawings are provided to facilitate the reader'sunderstanding of the disclosed technology and shall not be consideredlimiting of the breadth, scope, or applicability thereof. It should benoted that for clarity and ease of illustration these drawings are notnecessarily made to scale.

FIG. 1 is a diagram illustrating a typically outdoor unit.

FIG. 2 is a diagram illustrating an example implementation of a lownoise block.

FIG. 3 is a diagram illustrating another example of a low noise block(LNB).

FIG. 4 is a diagram illustrating an example of an LNB in accordance withone embodiment of the technology disclosed herein.

FIG. 5 is a diagram illustrating another example of an LNB, butconfigured to handle 3 satellites, each having left and rightpolarizations.

FIG. 6, which comprises FIGS. 6A and 6B, is a diagram illustrating anexample of a shared analog-to-digital converter in accordance with oneembodiment of the technology disclosed herein.

FIG. 7, which comprises FIGS. 7A and 7B, is a diagram illustrating anexample of implementing a combiner with a shared ADC in an LNB IC.

FIG. 8 is a block diagram illustrating an example of cross-couplingsignal cancellation in accordance with one embodiment of the technologydisclosed herein.

FIG. 9 is a diagram illustrating an example implementation ofcross-coupling signal cancellation in accordance with one embodiment ofthe technology disclosed herein.

FIG. 10 is a diagram illustrating the details of an example adaptivefilter.

FIG. 11 is an operational flow diagram illustrating an example processfor cross-coupling signal cancellation in accordance with one embodimentof the technology disclosed herein.

FIG. 12 is an operational flow diagram illustrating another exampleprocess for cross-coupling signal cancellation in accordance with oneembodiment of the technology disclosed herein.

FIG. 13 is a diagram illustrating an example of three transpondersreceived as part of a satellite signal.

FIG. 14 is a diagram illustrating an example process for adjusting theoscillator frequency to correct for changes in the center channelfrequency in accordance with one embodiment of the technology disclosedherein.

FIG. 15 is a diagram illustrating an example of a DRO in accordance withone embodiment of the technology disclosed herein.

FIG. 16 is a diagram illustrating another example of a dielectricresonator oscillator that may be implemented in accordance with variousembodiments of the technology disclosed herein.

FIG. 17 is a diagram illustrating another example of a dielectricresonator oscillator that may be implemented in accordance with variousembodiments of the technology disclosed herein.

FIG. 18 is a diagram illustrating an example implementation of anintegrated DRO in accordance with one embodiment of the technologydisclosed herein.

FIG. 19 is another diagram illustrating the inclusion of active elementsof the dielectric resonator oscillator on a die and passive elements onthe substrate.

FIG. 20 is a diagram illustrating an example computing module which canbe used in accordance with various embodiments of the technologydescribed herein.

The figures are not intended to be exhaustive or to limit the inventionto the precise form disclosed. It should be understood that theinvention can be practiced with modification and alteration, and thatthe disclosed technology be limited only by the claims and theequivalents thereof.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiments of the technology disclosed herein are directed toward adevices and methods for providing techniques for improving satellitecommunications. More particularly, the various embodiments of thetechnology disclosed herein relate to improved LNB configurations.

FIG. 4 is a diagram illustrating an example of an LNB in accordance withone embodiment of the technology disclosed herein. The exampleillustrated in FIG. 4 is one of a single satellite implementation withVertical and Horizontal polarizations. In this example, the satellitesignals are Ku band satellite signals however, the LNB can be configuredfor use with other satellite bands. This example includes a low noiseblock (LNB) IC 250 that can be implemented, for example, on a single ormultiple integrated circuits. LNB IC 250 in this example includes analogvariable gain amplifiers 252, bandpass filters 254, analog-to-digitalconverters 255, a filtering, cross cancellation and matrix switch module257, digital-to-analog converters 258, a control and interface module259, a dielectric puck resonator 251, a local oscillator 253, and aclock generator 256. The LNB can also include low noise amplifiers (LNA)and bandpass filters (BPF), which can be implemented, for example, asLNAs 141 and BPFs 142.

In operation, the amplitude of the incoming signals is adjusted byvariable gain amplifiers 252 and unwanted noise outside of the desiredfrequency bands is removed by bandpass filters 254. The analog signal issampled by analog-to-digital converters 255 using a clock provided byclock generator 256. The resulting digital signals can be processed bymodule 257, which can provide further filtering, cross couplingcancellation, and switching to the designated output or outputs.Digital-to-analog converters 258 convert the outputs to digital form fordistribution to the set top boxes. LNB 250 can be configured andimplemented to perform what is sometimes referred to as channel stacking(CSS) as described in more detail below.

Various features of the technology disclosed herein can be implementedfor use in this example LNB as well as in other LNB configurations, aswill become apparent to one of ordinary skill in the art after readingthis description. For example, various features described in terms ofthis example LNB IC 250 can be implemented with quad, twin, single, andwideband LNB circuits. For a wideband LNB implementation, rather thanfour outputs at 950-2150 MHz, the LNB can be implemented with twooutputs, each at 290-2340 MHz IF each (each 2.05 GHz wide).

In some embodiments, the dielectric resonator can be implemented in anintegrated fashion with the LNB IC. As discussed further below, in someembodiments, the dielectric resonator oscillator, or DRO, can beintegrated with the IC package. Consider, for example, the case of aflip chip integrated circuit. In this application, the dielectric puckand associated transmission lines can be mounted on a substrate of theflip chip package all the active components of the DRO can be fabricatedas part of the integrated circuit die. Accordingly, the DRO can beconfigured to consume less real estate, require fewer discretecomponents (e.g. discrete transistors) and realize a lower productioncost. Likewise, the DRO can be implemented to provide a stabilizedreference frequency without the need for a PLL.

Another feature that can be implemented in various embodiments aresystems and methods for correcting frequency error in the localoscillator. As described below, embodiments can be implemented toprofile the incoming transponders spectral shape, or to identifyspectral nulls between transponders to determine and maintain theappropriate center frequency in a closed loop. Embodiments can beimplemented such that internal filters and the output frequency aredigitally corrected, while other embodiments are configured such thatthe local oscillator can be physically tuned to the correct centerfrequencies such as through the use of tuned or switched capacitors.

Another feature that can be implemented in various embodiments aresystems and methods for cross canceling and removing undesired crosscoupling of signals that may occur in the IC. In various embodiments,this can be done on a pin for pin basis such that cross coupling can bereduced or eliminated across adjacent pins or across other pin pairsover which cross coupling may occur. Embodiments can be implementedwhere the correction occurs on an ongoing basis through the use of powermeasurement and filter coefficient adjustment. The adjustment cancontinue until the measured power reaches a relative minimum.

Still another feature that can be implemented in various embodiments isdirect on-frequency sampling of the incoming signal at the satelliteband, with digital filtering, processing and routing. This can allow, ineffect, a direct downconversion and reduce the number of componentsotherwise required to implement the LNB.

Yet another feature that can be implemented in various embodiments isthat of shared analog-to-digital converters. In various embodiments,signals of different frequencies can be combined and sampled using oneanalog-to-digital converter as opposed to using multipleanalog-to-digital converters. Embodiments can be implemented to reducethe number of components required for the LNB IC.

FIG. 5 is a diagram illustrating another example of an LNB, this timeconfigured to handle 3 satellites, each having left and rightpolarizations. As with the example shown in FIG. 4, this exampleincludes one or more low noise amplifiers and bandpass filters at thefront end of the system. In the case of Ka band, two bandpass filterscan be used, one each signal to select the high and low bands of the Kaband. The example of FIG. 5 also includes an LNB IC 310. In thisexample, LNB IC 310 includes variable gain amplifiers 314, bandpassfilters 316, and analog-to-digital converters 318, and adigital-to-analog converter 320 at the output. This example alsoincludes a channel stacking switch (CSS) 311, which can be implemented,for example, part of LNB IC 310. Additionally, a control and interfacemodule 322 is included to provide control of CSS 311 and othercomponents of the LNB IC 310. A dielectric puck resonator 324 with theappropriate clock generation circuitry can also be provided. The variousfeatures described above that may be included in various embodiments ofLNB IC 250 may also be included with LNB IC 310.

As noted above, in various embodiments systems and methods can beimplemented to provide sharing of analog-to-digital converters (e.g.analog-to-digital converters 318 of FIG. 5) in the LNB. Particularly,embodiments can be implemented in which the signals of differentfrequencies can be combined together and then sampled using a singleADC. The resultant digital representation of the combined signals canthen be provided to the CSS (or other processing module) for furtherprocessing and handling. FIG. 6, which comprises FIGS. 6A and 6B, is adiagram illustrating an example of a shared analog-to-digital converterin accordance with one embodiment of the technology disclosed herein.The example of FIG. 6A is depicted in terms of two different satellitesignals, one at the Ka band and the other at the Ku band. Ka bandsignals are for example 18.3-18.8 GHz (low band), and 19.7-20.2 GHz(high band), while Ku band signals range from 12.2-12.7 GHz. The exampleof FIG. 6B is depicted in terms of 2 different WiFi signals, one at 2.4GHz and the other at 5 GHz. After reading this description, one ofordinary skill in the art will appreciate how the sharedanalog-to-digital converter techniques can be applied with signals atother frequency bands.

Turning first to FIG. 6A, for illustration purposes, the system is shownas having two low noise amplifiers 351 and two bandpass filters 352.These can, for example, represent the low noise amplifiers and bandpassfilters depicted in FIGS. 3 and 4 to the left of the inputs of the LNBICs. FIG. 6A also depicts a portion of an example LNB IC 350 toillustrate an embodiment of the shared analog-to-digital converter. Inthis example, LNB IC 350 includes two variable gain amplifiers 353, onefor each input signal. LNB IC 350 also includes two bandpass filters354, one for each input signal. A combiner 355 is provided to combinethe two input signals into a single analog signal. The combining can be,for example, a simple spectral combination of signals. The combiner 355can be implemented as a combiner, passive diplexer, or other device tomix together the two satellite signals. Preferably, the signals chosenfor combination are signals having frequencies that do not overlap withone another such that the combination does not provide unwantedinterference.

Because the signals are combined, they can be digitized for furtherprocessing using a single analog-to-digital converter 356. This iscontrasted with conventional solutions in which a separateanalog-to-digital converter would have been used for each input signal.The signal combining can be performed on or off chip, but is illustratedon chip in the example of FIG. 6A. An external frequency conversion canbe included to handle situations where incoming signals are at the samefrequencies. Accordingly, one (or both) of the signals can be convertedto a different frequency so that the frequencies of the two signals arenon-overlapping, allowing the combination by the combiner. For example,additional feeds at a given band can be downconverted (e.g. externally)to an intermediate frequency and then combined with another feed fromthe same band for shared sampling. In some embodiments, the samplingclock frequency for the analog-to-digital conversion is selected inbetween the Ka and the Ku bands. For example, the sampling clockfrequency can be selected at 15.85 GHz.

FIG. 6B is a diagram illustrating a similar configuration as in FIG. 6A,but configured for operating at WiFi frequencies. As illustrated in thisexample, the system is configured to combine signals at two differentWiFi frequencies, 2.4 GHz and 5 GHz, and to digitize the combined signalusing a single analog-to-digital converter 356. Although two specificbands are shown in this example, the shared analog-to-digital convertercan be implemented for combined signals from other multiple WiFi bandsincluding, for example, 3.6 GHz, 6 GHz, and so on.

It is noted that components 352-356 are illustrated using the samereference numerals as the Ka/Ku band implementation, to reflect similarfunctionality. However, as will be apparent to one of ordinary skill inthe art after reading this discussion, these components can be selectedand tuned to operate at the corresponding WiFi frequencies. For example,for sampling in different Nyquist zones, the sampling clock frequencycan be chosen between the 2.4 GHz and 5 GHz bands (e.g. at ^(˜)5 GHz).After sampling, the 2.4 GHz band (which falls into the first Nyquistzone) in the digital domain will remain at 2.4 GHz, while the 5 GHz band(located in the third Nyquist zone) is translated to approximately 0.8GHz. In another embodiment, the sampling clock frequency can be set atabove the 5 GHz band (e.g., at ^(˜)6 GHz), in which case, the 2.4 GHzband remains at 2.4 GHz after sampling, while the 5 GHz (now in thesecond Nyquist zone) is translated to about 0.2 GHz. Internal bandpassfiltering 354 can be provided to suppress aliasing of noise on to thedesired signal from other Nyquist zones and between the bands.Preferably, in various embodiments, the filters are centered at the WiFibands of interest. In other embodiments, the internal bandpass filters354 may be eliminated to simplify the architecture.

Although the examples above in FIGS. 6A and 6B are illustrated in termsof combining two signals, embodiments can be implemented in which two ormore signals are combined. In various embodiments, the signals can belevel adjusted using, for example, the variable gain amplifier 353 (e.g.automatic gain control) prior to combining. Signal combination can, forexample, be direct wired-OR combining such as by using diplexing filtersconnected to the same point. In other embodiments, the signal combiningcan be accomplished using a summing circuit. Clock frequencies forsampling can be chosen in various embodiments to place the multiplebands in different Nyquist zones, while in other embodiments the clockfrequency can be chosen to place the bands in a first Nyquist zone.

FIG. 7, which comprises FIGS. 7A and 7B, is a diagram illustratingexample implementations of a combiner with a shared ADC. An example ofimplementing a combiner with the shared ADC in an LNB IC is illustratedin FIG. 7A, while an example of implementing a combiner with the sharedADC in a WiFi IC is illustrated in FIG. 7B. Referring now to FIG. 7A, inthis example LNB IC 310 still includes signal inputs for threesatellites: two at Ka band and one at the Ku band. Because the Ku bandand Ka band satellite signals are at different frequencies, they can becombined without any appreciable interference. Accordingly, onepolarization of the Ku band signal is combined with one polarization ofthe Ka band signal at a first combiner 355A, and the combined signal isconverted by the first analog-to-digital converter 356A, and the digitalsignal is provided to the CSS 311. Similarly, the other polarization ofthe Ku band signal is combined with the other polarization of the Kaband signal at second combiner 355B. The combined signal is likewisedigitized by analog-to-digital converter 356B. When compared to theexample of FIG. 5, the example of FIG. 7A includes two feweranalog-to-digital converters while only adding to combiners.

As noted above, embodiments can be implemented in which a frequencytranslation is performed to separate two signals in frequency such thatthey can be combined with a single analog-to-digital converter.Accordingly, in such embodiments, the implementation of FIG. 7A could befurther modified to adjust the frequency of either or both of the Kaband signals 321, 323, and to combine the adjusted signals using acombiner (e.g. like combiner 355) to route the combined signal through asingle analog-to-digital converter. For example, in some embodiments,one of the signals can be downconverted to an intermediate frequencyprior to being combined.

Referring now to FIG. 7B, in this example a WiFi IC 410 includes signalinputs and outputs for two WiFi frequencies. Those are WiFi frequenciesof 5 GHz and 2.4 GHz. Because the signals are at different frequencies,they can be combined on the receive side without any appreciableinterference. Accordingly when switches 422, 423 for each band are setto the receive position, signals from both the 5 GHz and 2.4 GHzantennas are routed through the respective variable gain amplifiers 353and bandpass filters 354, and are combined by combiner 355 so that theycan be sampled using a single analog-to-digital converter 356. As notedabove, the variable gain amplifiers, bandpass filters, combiners, analogto digital converters and sampling clocks are selected and tuned basedon the operating frequencies of the WiFi signals. As this exampleillustrates, a single analog-to-digital converter can be used to supporta multi-band concurrent WiFi architecture. Additionally, greater thantwo bands can be supported provided the frequencies will not interferewith one another when the signals are combined, or provided thatpotentially interfering frequencies are translated to a non-interferingfrequency prior to combining. Although one antenna for each band isshown in this example, multiple MIMO antennas can be served with asimilar architecture repeated for each antenna. For example, in oneembodiment, the system can be configured to support a 4×4 MIMO in the 5GHz band in a 2×2 MIMO in the 2.4 GHz band. As this example serves toillustrate, other MIMO configurations in frequency bands can besupported.

Another feature that can be included in one or more embodiments issignal cancellation to reduce or eliminate cross coupling effects. Withhigh-frequency signal such as those involved in satellite reception anddistribution systems cross coupling can occur between adjacent signals.This can occur at numerous places along the downlink path between thesatellites and set-top boxes. One place that such cross coupling mayalso occur is that the LNB. Particularly, satellite signals on adjacentpins of an LNB IC or otherwise on signal paths close enough to allowcross coupling may experience this effect. Accordingly, techniques canbe implemented to reduce or eliminate the effects of cross coupling.FIG. 8 is a block diagram illustrating an example of cross-couplingsignal cancellation in accordance with one embodiment of the technologydisclosed herein. Referring now to FIG. 8, this example illustrates aportion of an LNB 400 with an LNB IC 410. LNB IC 410 can be implemented,for example, using an LNB IC such as LNB IC 310 described above.Accordingly, LNB IC 410 includes variable gain amplifiers, bandpassfilters and analog-to-digital converters. LNB IC 410 can also include aCSS module (e.g. CSS 311) that can further include a module forcross-coupling signal cancellation.

In various embodiments, the cross-coupling signal cancellation modulecan be configured to reduce or eliminate cross coupling of the inputsignals that may occur in the air, in the feed horn, on the printedcircuit board, in the power supply, on the IC pins, and so on. Thisresult of this coupling, the signals at d1 and d2 may be crosscontaminated in that each signal may contain some energy from the othersignal. As a result of cross-coupling signal cancellation module,outputs D1, D2 can be a cleaned-up signal with cross contaminationremoved or suppressed.

The cross-coupling signal cancellation can be implemented usingknowledge of the interfering signal. Particularly, a first of the twosignals can be inverted and combined with a delayed version of the otherof the two signals to cancel out (partially or completely) theinterfering signal. The amount of delay is chosen such that the invertedsignal aligns with the non-inverted version of that signal such thatcancellation can occur. In addition, the amplitude of the invertedsignal can be adjusted to adjust the level of cancellation. Adaptivefilters can be used to make phase and amplitude adjustments at theappropriate frequency or frequencies.

FIG. 9 is a diagram illustrating an example implementation ofcross-coupling signal cancellation in accordance with one embodiment ofthe technology disclosed herein. Particularly, FIG. 9 illustrates anexample module that can be used to implement cross-coupling signalcancellation module 411 of FIG. 8. In this example, the potentiallyinterfering signals are designated by d1 and d2. For ease of discussion,this example will be discussed in terms of d1 being an original signaland d2 being the interfering signal. However, after reading thisdescription, one of ordinary skill in the art will understand thateither signal can interfere with the other signal. Referring now to FIG.9, the original signal is received and delayed using delay block 462.Delay block 462 can be implemented using any of a number of conventionaldelay techniques including, for example, delay lines or, in digitalimplementations, by simply storing or holding the signal in a buffer orregister. Interfering signal d2 is modified by adaptive filter 463particularly, adaptive filter 463 inverts the interfering signal tocreate an inverse of the interfering signal. The phase and amplitudeadjustments can be made by changing the tap weights using tap weightvector computation block 468. Then, the filtered interfering signal issubtracted from the delayed original signal using subtraction block 466.Alternatively, the interfering signal can also be inverted and addedinto the original signal to effectively subtract the interfering signalfrom the original signal.

For cross coupling of signal d1 onto signal d2, a similar processoccurs, but in this instance, signal d1 is filtered using adaptivefilter 465, and original signal d2 is delayed using delay module 464.

FIG. 10 is a diagram illustrating the details of one of the adaptivefilters 463, 465, for example adaptive filter 463. The Z⁻¹ term denotesa delay by one clock cycle T. The weight components W¹, W² are stored incorresponding adaptive filters 463, 465. Each TWV component W¹, W² isthen provided by the weight setting register 501 to a plurality ofweighting circuits 505 in each of the corresponding adaptive filters463, 465. Each of the weighting circuits 505 adjusts the amount of thesignal x(n) at each delay point that is to be summed together in asumming circuit 510 based on the particular value of the TWV componentsW¹, W² associated with that weighting circuit, or adaptive filter 463,465. Accordingly, the output signal y(n) is the weighted sum of thevarious delays of x(n):

y(n)= w ₀*(n)x(n)+ w ₁*(n)x(n−1)+ . . . + w _(N-1)*(n)x(n−N+1);

W (n+1)= W (n)+2μe*(n) x (n);

where W(n+1) is the tap-weight vector next value at time n+1, the term μis the adaptation step size and the e*(n) is the conjugate of theresidue error value.

As noted above, in various embodiments cross coupling cancellation canoccur for signals (e.g., signals d1, d2) on adjacent pins of the LNB IC,or for cross coupling occurs in other places up to the CSS. Forpin-to-pin cancellation, the cancellation can occur for each adjacentpair of pins carrying satellite signals. In further embodiments, thecancellation can occur for all permutations of pairs of pins carryingsatellite signals. In yet another embodiment, the cancellation can beimplemented for pairs of pins likely to interfere with one another. Toprevent potential instability and oscillatory behavior of multiple loopsinterfering with each other, when one loop is making adjustments, otherloops are “frozen” (kept constant without making changes). After theaction of the active loop is completed, another loop becomes activewhile others are frozen. The process continues until all loops arecompleted, then the maintenance cycle repeats. An additional benefit ofprocessing one loop at the time is in reduced computational complexity,since a single computational engine can be shared between multipleloops, as opposed to the case of simultaneously processing multipleloops, when multiple computational engines would be required.

FIG. 11 is an operational flow diagram illustrating an example processfor cross-coupling signal cancellation in accordance with one embodimentof the technology disclosed herein. In this example, the success of thecancellation, and hence the adjustment of the filter coefficients, canbe made based on a measurement of the total output power. Because theoutput power of a given signal includes the power of the signal itselfas well as the added power contributed by the cross coupled signal, whenthe output power is minimized (assuming all other factors remain equal,this indicates that the cross coupling is also minimized. Accordingly,an iterative least mean squares process can be implemented to adjust thefilter coefficients to achieve a minimum power. This can be done on anongoing basis, if desired, during operations.

Referring now to FIG. 11 at a step 602 the total output power ismeasured. In one embodiment, as illustrated by operation 604, the outputpower can be integrated and measured over a predefined period of time todetermine the total output power. This can allow a power to be observedover a longer period of time.

At operation 604, the filter coefficients are adjusted for theinterfering signal to adjust the phase and amplitude of the interferingsignal. For example, in terms of the embodiment illustrated in FIG. 9,the filter coefficients of adaptive filter 463 are adjusted. Atoperation 606, the filtered interfering signal is combined with theoriginal signal to cancel the cross coupled interference from theoriginal signal. That is, the filtered interfering signal, adjusted inamplitude to approximate the amplitude of the cross couplinginterference in the original signal, is subtracted from (or its inverseis added to) the original signal. The power is again measured todetermine whether it is minimized. This is illustrated by operations 608and 610. The operation continues until the power is minimized. In someembodiments, the operation continues to run in a self-adjusting fashion,maintaining the power at minimum. Where the power is at a minimum, thechanges to the filter coefficients will be minimal as well, therebyholding the system approximately in a steady state.

Interference on a given satellite signal can result not only from crosscoupling of one adjacent signal, but can also be affected by anotheradjacent signal. For example, each pin of an LNB IC generally has twoadjacent neighbor pins. Accordingly, it may be desirable to cancel outcross coupling that may result from signals on these two adjacentneighbor pins. Accordingly, in some embodiments, a process similar tothat described above with reference to FIG. 11 can be implemented forthe signal on the subject pin and one of its adjacent neighbors. Then,once the cross coupling is minimized (e.g. the output power isminimized) the filter coefficients for the first neighbor pin are heldconstant and the process is repeated for the original pin and the othernearest neighbor pin. This process can be expanded to account for crosscoupling onto a given pin by signals in addition to those of theadjacent pins. For example, the process may consider cross couplingeffects on a given pin as a result of signals on a plurality of otherpins or signal paths near enough to the subject pin to result inappreciable cross coupling.

An example of this is illustrated in FIG. 12. Referring now to FIG. 12,as noted the process focuses on cross coupling between a given pair ofpins. This can be, for example, a pair of nearest neighbor pins, oranother pair of pins across which cross coupling may occur. Accordingly,any adjustments to filter coefficients for the effects caused by signalson other pins (other than the pair under immediate consideration) areheld constant. This is illustrated by operation 652. As described abovewith reference to FIG. 11, the total output power is measured, and thefilter coefficients adjusted for the interfering signal. This isillustrated at operation 654, 656. As also described above withreference to FIG. 11, the signals are combined in the power levelmeasured to minimize the power at the output of the subject signal. Thisis illustrated at operations 657 and 658.

Once the cross coupling effect on a signal on a selected pin by a signalon first pin is minimized as described immediately above, the processcan be repeated for a second pin. Accordingly, the filter coefficientsas determined for the first pin are held constant and the filtercoefficients for the second pin are adjusted to minimize the power. Thisis illustrated at operations 659, 660, 662. Where interference on agiven pin is only addressed for that caused by two other pins (e.g. thenearest-neighbor pins) the operation may be done. However, inembodiments where interference as a result of signals on a number ofdifferent pins is being addressed, the process can repeat for each pairof pins under consideration. This is illustrated by operation 665. Forexample, in some embodiments, the operation can be repeated such that ppairs of satellite signals are considered, where p comprises a number ofpossible pairings of satellite signals in the LNB (or the number ofpairings likely to give rise to appreciable interference. For example,where interference is being considered across each possible pairing ofpins bearing satellite signals, the operation is performed for p pairsof satellite signals, where p is given by n!/2(n−2), and where n is thenumber of satellite signals under consideration.

In various embodiments the amplitude of the cancellation signal isadapted to approximate the amplitude of the cross coupling signalaffecting the signal under consideration. In some embodiments,convergence may occur more quickly where the filter coefficients arechosen such that the starting point for the amplitude is estimated asclose as possible to the predicted level of interference caused by thecross coupling. Accordingly, parameter such as the distance betweensignal pairs and the frequency of the interfering signal can be takeninto consideration when setting the initial filter coefficients.

As noted above, in various embodiments another feature that can beincluded is the ability to correct the frequency of the localoscillator, or ultimately, of the clocks used to sample theanalog-to-digital converters. Embodiments of the technology disclosedherein accomplish this, in part, based on knowledge of the transpondersreceived with the satellite signal. Because transponder characteristicssuch as center frequency and bandwidth are well defined, thesecharacteristics can be used to identify the center frequency using thereceived signal. Generally speaking, in some embodiments, the system canbe configured to receive the satellite signal with a known predefinedbandwidth and a center frequency, determine the profile of the satellitesignal, and compute the center frequency of the satellite signal basedon the profile of the received signal. Once that is accomplished, thesystem can be configured to generate a reference signal at the computedcenter frequency.

FIG. 13 is a diagram illustrating an example of three transpondersreceived as part of a satellite signal. As seen in this example at13(a), each transponder has a center frequency, f_(c), and a definedbandwidth 710. The spacing between the center frequencies of eachtransponder is known as is the bandwidth. The transponder centerfrequency is typically very stable, and as such can be used as areference for the local oscillator frequency. The oscillator may have aninaccurate frequency due to component tolerances, as well as itsfrequency can drift as a result of temperature variations or instabilityover time and aging. As a result of the tolerance and drift, localoscillator frequency, f_(LO), is offset from transponder centerfrequency, f_(c), by an unknown amount. Therefore, the known spectralshape of the transponder can be used to identify the center frequency.

FIG. 14 is a diagram illustrating an example process for adjusting theoscillator frequency to correct for changes in the center channelfrequency in accordance with one embodiment of the technology disclosedherein. With reference now to FIG. 14 at operation 712, a transponder isselected. At operation 714, the tuning for that transponder is sweptabove and below the reference frequency generated directly or indirectlyby the oscillator. This is, for example, the estimated center channelfrequency for the transponder. A purpose of sweeping above and below thereference frequency is to profile the amplitude response of thetransponder. For example, the system can be configured to determine theupper and lower rolloff points of the received transponder signal basedon, for example, measured signal strength. Because the center frequencyis midway between the upper and lower rolloff points, the centerfrequency can be determined based on this profiling. This is illustratedby operation 716. At operation 718, the oscillator can be tuned to thecenter frequency, or otherwise adjusted such that derivatives thereof(e.g., generated by frequency multipliers or dividers) will be at orsubstantially at a center frequency of the transponder. For example, avaractor may be used to tune the oscillator or, capacitors and a bank ofcapacitors can be switched in or out of the circuit to tune theoperating frequency.

Alternatively, the LO frequency is not tuned to the correct centerfrequency, rather the frequency error is computed and digitally appliedand proportionally corrected in all stages that need to have accuratefrequency. For example the output frequency at the output of the DAC isproportionally offset to the correct value, while the DAC clock itselfis still uncorrected. Accordingly, in such embodiments, implementationscan be accomplished in which no physical tuning elements are needed, andthe correction is accomplished computationally.

Once the center frequency of a given transponder is determined, thecenter frequencies of the other transponders can be determined based onthe known spacing between transponder center frequencies. This isillustrated at operation 720. Although it may be easier to calculate thecenter frequencies or other transponders based on known separations, inother embodiments, the process described above for sweeping andprofiling transponders can be repeated for each transponder.

In one embodiment, to avoid transponder ambiguity, the outertransponders (i.e. the first or the last transponder in the band) arechosen for the above calibration process. In another embodiment, whenthe LO frequency f_(LO) has an error less than half transponder width,any transponder can be used for calibration.

In another embodiment, rather than profiling based on rolloff points,the system can be configured to measure the signal strength during thesweeping operation and determine spectral nulls of one or moretransponder signals. Once the spectral nulls, or minimum power points inthe spectrum, are identified the center frequency can again bedetermined, for example, as the midpoint between the spectral nulls.

In various embodiments, centering of the LO frequency for WiFi systemmay be accomplished in a similar manner as described above for satelliteimplementations. In the case of WiFi implementations, the channelprofiles used for the frequency sweep and analysis are those asspecified for WiFi channels as opposed to the satellite transponderprofiles.

Another feature as noted above that can be included in variousembodiments of the technology disclosed herein includes a dielectricoscillator to provide the clock frequencies used at least for samplingby the analog-to-digital converters and digital-to-analog converters.The clock can be provided directly by the oscillator or throughmultiplier or divider circuits to provide the desired clock rate. Insome embodiments, the oscillator can be configured as a dielectricresonator oscillator (DRO). A dielectric resonator typically comprises adielectric material (e.g., ceramic or other dielectric) that relies on achange in permittivity at its surface to confine electromagnetic wavesfor resonance. That is, standing waves can be created within thedielectric material. In various embodiments, the dielectric resonator isa cylindrical material sometimes referred to as a “puck.” Preferably,the puck has a large dielectric constant and a relatively lowdissipation factor. The dimensions of the resonator, or puck, are chosenbased on the desired resonant frequency. The dielectric resonatorprovides frequency stabilization at the resonant frequency and typicallyallows a high Q. The DRO is achieved by combining resonating elements(L, C or R) coupled to an active device such as, for example, atransistor. The feedback element can be included to reflect the standingwave within the resonating element.

FIG. 15 is a diagram illustrating an example of a DRO in accordance withone embodiment of the technology disclosed herein. Referring now to FIG.15, this example includes a dielectric resonator 810, a transmissionline 811, a feedback element 815, and a matching network 822. In variousembodiments, feedback element 815 and matching network 822 may bereferred to as active elements 850. Active elements 850 may also includetransistor 818. Transistor 818 may include, for example, a Si-bipolartransistor, GaAs FET, or CMOS transistor.

In operation, a signal is input on transmission line 811. Transmissionline 811 can be, for example, a microstrip transmission line.Transmission line 811 is ideally configured as having a length at aquarter wavelength (or integer multiples thereof) of the desiredresonant frequency. Dielectric resonator 810 can, for example, beconfigured as a dielectric puck made of a dielectric material such as,for example, ceramic, porcelain, glass, plastic, or polymer materialshaving dielectric properties. Feedback element 815 can be provided toreflect the signal back onto transmission line 811 for resonance.Matching network 822 can be included to match the resonator to the load(represented in this example by resistor R_(L)).

FIG. 16 is a diagram illustrating another example of a dielectricresonator oscillator that may be implemented in accordance with variousembodiments of the technology disclosed herein. In the exampleillustrated in FIG. 16, two transmission lines 811 are provided to forma resonant circuit along with the dielectric resonator 810 and feedbackelement 813. In another example, the resistor between the twotransmission lines 811 is removed, leaving the lines open-circuited.

FIG. 17 is a diagram illustrating another example of a dielectricresonator oscillator that may be implemented in accordance with variousembodiments of the technology disclosed herein. In this example, the twotransmission lines 811 are open, unterminated on the input side.

In various embodiments, advantages can be obtained where the dielectricresonator oscillator is integrated as part of the IC package. Forexample, in some embodiments some or all of the active elements can beincluded in the die of the LNB IC. The passive components (e.g., thedielectric resonator 810 in one or more transmission lines 811) may bemounted in close proximity to the die such as on the printed circuitboard or, on the substrate of the integrated circuit package where theintegrated circuit package is a flip chip package. FIG. 18 is a diagramillustrating an example implementation of an integrated DRO inaccordance with one embodiment of the technology disclosed herein. Withreference now to FIG. 18, illustrated in this example is the generalconfiguration of a flip chip package 870 including a substrate 865 and adie 860. As this example illustrates active elements 850 of the DRO canbe integrated as part of the die. That is, they can be fabricated alongwith the other circuitry that makes up the LNB IC. As this example alsoillustrates, dielectric resonator 810 and one or more transmission lines811 can be included on the substrate 865 of the LNB IC (e.g., flip chip870). For clarity of illustration, the interconnects between thecomponents mounted on the substrate and active elements 850 are notillustrated in this example. However, the electrical interconnects areschematically represented in FIGS. 15, 16, and 18, and given thisdescription, one of ordinary skill in the art will understand how tointerconnect one or more transmission lines 811 within input and withactive elements 850.

FIG. 19 is another diagram illustrating the inclusion of active elementsof the dielectric resonator oscillator on a die and passive elements onthe substrate. Although not illustrated in FIG. 19, in anotherembodiment dielectric resonator, or puck, 810 can be mounted on theprinted circuit board adjacent the semiconductor package. In such anembodiment, the one or more transmission lines 811 would be configuredas having sufficient length to run from a position adjacent thedielectric resonator 810 to the substrate of the integrated circuitpackage.

As used herein, the term module might describe a given unit offunctionality that can be performed in accordance with one or moreembodiments of the technology disclosed herein. As used herein, a modulemight be implemented utilizing any form of hardware, software, or acombination thereof. For example, one or more processors, controllers,ASICs, PLAs, PALs, CPLDs, FPGAs, logical components, software routinesor other mechanisms might be implemented to make up a module. Inimplementation, the various modules described herein might beimplemented as discrete modules or the functions and features describedcan be shared in part or in total among one or more modules. In otherwords, as would be apparent to one of ordinary skill in the art afterreading this description, the various features and functionalitydescribed herein may be implemented in any given application and can beimplemented in one or more separate or shared modules in variouscombinations and permutations. Even though various features or elementsof functionality may be individually described or claimed as separatemodules, one of ordinary skill in the art will understand that thesefeatures and functionality can be shared among one or more commonsoftware and hardware elements, and such description shall not requireor imply that separate hardware or software components are used toimplement such features or functionality.

Where components or modules of the technology are implemented in wholeor in part using software, in one embodiment, these software elementscan be implemented to operate with a computing or processing modulecapable of carrying out the functionality described with respectthereto. One such example computing module is shown in FIG. 20. Variousembodiments are described in terms of this example-computing module 900.After reading this description, it will become apparent to a personskilled in the relevant art how to implement the technology using othercomputing modules or architectures.

Referring now to FIG. 20, computing module 900 may represent, forexample, computing or processing capabilities found within desktop,laptop and notebook computers; hand-held computing devices (PDA's, smartphones, cell phones, palmtops, etc.); mainframes, supercomputers,workstations or servers; or any other type of special-purpose orgeneral-purpose computing devices as may be desirable or appropriate fora given application or environment. Computing module 900 might alsorepresent computing capabilities embedded within or otherwise availableto a given device. For example, a computing module might be found inother electronic devices such as, for example, digital cameras,navigation systems, cellular telephones, portable computing devices,modems, routers, WAPs, terminals and other electronic devices that mightinclude some form of processing capability.

Computing module 900 might include, for example, one or more processors,controllers, control modules, or other processing devices, such as aprocessor 904. Processor 904 might be implemented using ageneral-purpose or special-purpose processing engine such as, forexample, a microprocessor, controller, or other control logic. In theillustrated example, processor 904 is connected to a bus 902, althoughany communication medium can be used to facilitate interaction withother components of computing module 900 or to communicate externally.

Computing module 900 might also include one or more memory modules,simply referred to herein as main memory 908. For example, preferablyrandom access memory (RAM) or other dynamic memory, might be used forstoring information and instructions to be executed by processor 904.Main memory 908 might also be used for storing temporary variables orother intermediate information during execution of instructions to beexecuted by processor 904. Computing module 900 might likewise include aread only memory (“ROM”) or other static storage device coupled to bus902 for storing static information and instructions for processor 904.

The computing module 900 might also include one or more various forms ofinformation storage mechanism 910, which might include, for example, amedia drive 912 and a storage unit interface 920. The media drive 912might include a drive or other mechanism to support fixed or removablestorage media 914. For example, a hard disk drive, a floppy disk drive,a magnetic tape drive, an optical disk drive, a CD or DVD drive (R orRW), or other removable or fixed media drive might be provided.Accordingly, storage media 914 might include, for example, a hard disk,a floppy disk, magnetic tape, cartridge, optical disk, a CD or DVD, orother fixed or removable medium that is read by, written to or accessedby media drive 912. As these examples illustrate, the storage media 914can include a computer usable storage medium having stored thereincomputer software or data.

In alternative embodiments, information storage mechanism 910 mightinclude other similar instrumentalities for allowing computer programsor other instructions or data to be loaded into computing module 900.Such instrumentalities might include, for example, a fixed or removablestorage unit 922 and a storage unit interface 920. Examples of suchstorage units 922 and a storage unit interfaces 920 can include aprogram cartridge and cartridge interface, a removable memory (forexample, a flash memory or other removable memory module) and memoryslot, a PCMCIA slot and card, and other fixed or removable storage units922 and a storage unit interfaces 920 that allow software and data to betransferred from the storage unit 922 to computing module 900.

Computing module 900 might also include a communications interface 924.Communications interface 924 might be used to allow software and data tobe transferred between computing module 900 and external devices.Examples of communications interface 924 might include a modem orsoftmodem, a network interface (such as an Ethernet, network interfacecard, WiMedia, IEEE 802.XX or other interface), a communications port(such as for example, a USB port, IR port, RS232 port Bluetooth®interface, or other port), or other communications interface. Softwareand data transferred via communications interface 924 might typically becarried on signals, which can be electronic, electromagnetic (whichincludes optical) or other signals capable of being exchanged by a givencommunications interface 924. These signals might be provided tocommunications interface 924 via a channel 928. This channel 928 mightcarry signals and might be implemented using a wired or wirelesscommunication medium. Some examples of a channel might include a phoneline, a cellular link, an RF link, an optical link, a network interface,a local or wide area network, and other wired or wireless communicationschannels.

In this document, the terms “computer program medium” and “computerusable medium” are used to generally refer to media such as, forexample, memory 908, storage unit 922, media 914, and channel 928. Theseand other various forms of computer program media or computer usablemedia may be involved in carrying one or more sequences of one or moreinstructions to a processing device for execution. Such instructionsembodied on the medium, are generally referred to as “computer programcode” or a “computer program product” (which may be grouped in the formof computer programs or other groupings). When executed, suchinstructions might enable the computing module 900 to perform featuresor functions of the disclosed technology as discussed herein.

While various embodiments of the disclosed technology have beendescribed above, it should be understood that they have been presentedby way of example only, and not of limitation. Likewise, the variousdiagrams may depict an example architectural or other configuration forthe disclosed technology, which is done to aid in understanding thefeatures and functionality that can be included in the disclosedtechnology. The disclosed technology is not restricted to theillustrated example architectures or configurations, but the desiredfeatures can be implemented using a variety of alternative architecturesand configurations. Indeed, it will be apparent to one of skill in theart how alternative functional, logical or physical partitioning andconfigurations can be implemented to implement the desired features ofthe technology disclosed herein. Also, a multitude of differentconstituent module names other than those depicted herein can be appliedto the various partitions. Additionally, with regard to flow diagrams,operational descriptions and method claims, the order in which the stepsare presented herein shall not mandate that various embodiments beimplemented to perform the recited functionality in the same orderunless the context dictates otherwise.

Although the disclosed technology is described above in terms of variousexemplary embodiments and implementations, it should be understood thatthe various features, aspects and functionality described in one or moreof the individual embodiments are not limited in their applicability tothe particular embodiment with which they are described, but instead canbe applied, alone or in various combinations, to one or more of theother embodiments of the disclosed technology, whether or not suchembodiments are described and whether or not such features are presentedas being a part of a described embodiment. Thus, the breadth and scopeof the technology disclosed herein should not be limited by any of theabove-described exemplary embodiments.

Terms and phrases used in this document, and variations thereof, unlessotherwise expressly stated, should be construed as open ended as opposedto limiting. As examples of the foregoing: the term “including” shouldbe read as meaning “including, without limitation” or the like; the term“example” is used to provide exemplary instances of the item indiscussion, not an exhaustive or limiting list thereof; the terms “a” or“an” should be read as meaning “at least one,” “one or more” or thelike; and adjectives such as “conventional,” “traditional,” “normal,”“standard,” “known” and terms of similar meaning should not be construedas limiting the item described to a given time period or to an itemavailable as of a given time, but instead should be read to encompassconventional, traditional, normal, or standard technologies that may beavailable or known now or at any time in the future. Likewise, wherethis document refers to technologies that would be apparent or known toone of ordinary skill in the art, such technologies encompass thoseapparent or known to the skilled artisan now or at any time in thefuture.

The presence of broadening words and phrases such as “one or more,” “atleast,” “but not limited to” or other like phrases in some instancesshall not be read to mean that the narrower case is intended or requiredin instances where such broadening phrases may be absent. The use of theterm “module” does not imply that the components or functionalitydescribed or claimed as part of the module are all configured in acommon package. Indeed, any or all of the various components of amodule, whether control logic or other components, can be combined in asingle package or separately maintained and can further be distributedin multiple groupings or packages or across multiple locations.

Additionally, the various embodiments set forth herein are described interms of exemplary block diagrams, flow charts and other illustrations.As will become apparent to one of ordinary skill in the art afterreading this document, the illustrated embodiments and their variousalternatives can be implemented without confinement to the illustratedexamples. For example, block diagrams and their accompanying descriptionshould not be construed as mandating a particular architecture orconfiguration.

1. A method for canceling cross-coupled satellite signals in a LNB IC,the method comprising: receiving a first satellite signal at a first pinof the LNB IC and adjusting the first satellite signal by applying afirst adaptive filter to the first satellite signal, the first adaptivefilter having first filter coefficients; combining the adjusted firstsatellite signal with a second satellite signal received at a second pinof the LNB IC to generate a first combined satellite signal; measuringthe total output power of the combined satellite signal; changing thefilter coefficients of the first adaptive filter; remeasuring the totaloutput power of the first combined satellite signal after the changingof the first filter coefficients to determine whether the total power ofthe first combined satellite signal has decreased.
 2. The method ofclaim 1, further comprising delaying the second received satellitesignal prior to combining it with the adjusted first satellite signal.3. The method of claim 1, further comprising repeating the operations ofchanging the filter coefficients and remeasuring the total output powerof the first combined satellite signal after the change until themeasured total output power reaches a minimum value.
 4. The method ofclaim 1, further comprising repeating the operations of changing thefirst filter coefficients and remeasuring the total output power of thefirst combined satellite signal after the change.
 5. The method of claim1, further comprising minimizing the total output power of the firstcombined satellite signal by repeating the operations of changing thefirst filter coefficients and remeasuring the total output power of thefirst combined satellite signal until a minimum power level is reached.6. The method of claim 1, wherein the first adaptive filter applied is aleast mean square filter.
 7. The method of claim 1, further comprisingrepeating the operation for additional pairs satellite signals.
 8. Themethod of claim 1, further comprising repeating the operation for aremaining number of p pairs of satellite signals, where p comprises anumber of possible pairings of satellite signals in the LNB.
 9. Themethod of claim 1, further comprising repeating the operation for aremaining number of pairs of p pairs of satellite signals, where p isgiven by n!/2(n−2), where n is the number of satellite signals underconsideration.
 10. The method of claim 7, further comprising adjustingthe second satellite signal by applying a second adaptive filter to thesecond satellite signal, the second adaptive filter having second filtercoefficients; combining the adjusted second satellite signal with thefirst satellite signal received at the first pin of the LNB IC to form asecond combined signal; measuring the total output power of the secondcombined satellite signal; changing the filter coefficients of thesecond adaptive filter; remeasuring the total output power of the secondcombined satellite signal after the changing of the second filtercoefficients to determine whether the total power the second combinedsatellite signal has decreased.
 11. A low noise block IC, comprising: aplurality of input pins each configured to receive a satellite signal; aplurality of delay modules, each delay module having an input coupled toa corresponding input pin and an output to output a delayed satellitesignal; a plurality of adaptive filter modules, each adaptive filtermodule having an input coupled to a corresponding input pin; a pluralityof signal combiners, each signal combiner having inputs coupled to anoutput of a corresponding delay module and an output of a correspondingadaptive filter module, and each signal combiner configured to output acombined satellite signal; a filter coefficient computation module,comprising computer executable program code embodied on a non-transitorymedium and configured to cause the filter coefficient computation moduleto perform the operations of: measuring the total output power of thecombined satellite signal from a first one of the plurality of signalcombiners; changing the filter coefficients of the adaptive filtercorresponding to the first one of the plurality of signal combiners;remeasuring the total output power of the combined satellite signal fromthe first one of the plurality of signal combiners after the operationof changing the filter coefficients to determine whether the total powerof the combined satellite signal from the first one of the p signalcombiners has decreased.
 12. The low noise block IC of claim 11, whereinthe computer executable program code is further configured to cause thefilter coefficient computation module to repeat the operations ofchanging the filter coefficients and remeasuring the total output powerof the first combined satellite signal after the change until themeasured total output power reaches a minimum value.
 13. The low noiseblock IC of claim 11, wherein the computer executable program code isfurther configured to cause the filter coefficient computation module torepeat the operations of changing the first filter coefficients andremeasuring the total output power of the first combined satellitesignal after the change.
 14. The low noise block IC of claim 11, whereinthe computer executable program code is further configured to cause thefilter coefficient computation module to perform the operations ofminimizing the total output power of the first combined satellite signalby repeating the operations of changing the first filter coefficientsand remeasuring the total output power of the first combined satellitesignal until a minimum power level is reached.
 15. The low noise blockIC of claim 11, wherein the first adaptive filter applied is a leastmean square filter.
 16. The low noise block IC of claim 11, wherein thecomputer executable program code is further configured to cause thefilter coefficient computation module to repeat the operations foradditional pairs satellite signals.
 17. The low noise block IC of claim11, wherein the computer executable program code is further configuredto cause the filter coefficient computation module to repeat theoperations for a remaining number of p pairs of satellite signals, wherep comprises a number of possible pairings of satellite signals in theLNB.
 18. The low noise block IC of claim 11, wherein the computerexecutable program code is further configured to cause the filtercoefficient computation module to repeat the operations for a remainingnumber of pairs of p pairs of satellite signals, where p is given byn″/2(n−2), where n is the number of satellite signals underconsideration.